Electronic – EA2-3NJ Relay won’t switch, what am I doing wrong

relay

I purchases a tube of EA2-3NJ relays from Mouser. Reputable company, not counterfeit parts, yada yada. I try using them with 3.3V coming off a Raspberry Pi and they won't switch. I tried several other 3.3V sources, can't get them to switch. I tried 10 different ones from the sleeve, no luck. Contacted Mouser, after a little back and forth, they sent me a replacement set. Same issue.

Here is the datasheet. The coil wants to be connected one way (+/-) and I am sure I am connecting it that way. I am not using a pulsed or waveformed voltage. The 3V model that I am using has a Must Operate Voltage of 2.25V. I tried voltages down to 2V and as high as 5V. Never switched. The contacts will handle 1A at 30V, I was using 5V connected to a couple of LEDs to test the circuit. I tried it both with and without a flyback diode.

So, I don't know what else to try. It's a relay, it's not rocket science. The only thing I can find in the datasheet that might suggest a problem is related to storage time — no more than 3 months at 70% relative humidity or 6 months at 50% relative humidity. So, could I have received two bad batches from Mouser or am I doing something wrong?

Best Answer

This kind of small relays are frequently have pre-polarized primary coil, to reduce the switch effort. And there could be a flyback diode inside as well. The datasheets show the bottom view of relays. And the application section states,

If the internal connection diagram of a relay shows + and − symbols on the coil, apply the rated voltage to the relay in the specified direction.

So, if it doesn't work, it is likely a misunderstanding of relay pinout, just try the opposite polarity.

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